CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 61/029,059, filed on Feb. 15, 2008, and U.S. Provisional Application No. 61/048,019, filed on Apr. 25, 2008, which are incorporated herein by reference.
FIELD OF THE INVENTION The present application relates to a rotary tool for polishing a surface.
BACKGROUND OF THE INVENTION Rotary polishing tools are available for polishing various surfaces. Such tools commonly have a substantially uniform size and shape making it difficult for a single polishing head to polish surfaces having varying sizes and shapes. For example, U.S. Pat. No. 7,203,989 B2, discloses a buffing and polishing ball made of a compressible polymeric foam material is formed by slitting a body of foam material in a substantially uncompressed state (1) from an outside surface of the body in a direction generally perpendicular to the rotational axis and (2) on circumferentially spaced planes that extend generally radially from the outside surface of the body to define a plurality of foam fingers. A fastening system is used to compress and hold a center portion of the foam body in a direction along the rotational axis such that the uncompressed outer ends of the finger assume a generally spherical ball.
In addition, U.S. Pat. No. 5,560,744 discloses a buffing apparatus including a buffing assembly including a stack of buffing wheels with or without spacers between the rings, compressed under high pressure. Each wheel includes a clinch ring which in turn secures an annulus of fabric extending radially therefrom. Each spacer includes a ring; they may be the remnants of used buffing wheels. The wheels and spacers, if any, are contiguous forming an inner cylindrical surface of the rings. Steel straps extend axially along this inner surface, the straps being secured by metal inert-gas welding to the rings at the ends of the stack. The pressure between the buffing wheels and any spacers of the stacks is so high as to suppress any tendency of the wheels or spacers to slip circumferentially with respect to each other when the stack is under high tangential force in use. The straps serve to be engaged by the keys of a drive shaft to drive the buffing apparatus.
Such shapes are not generally suitable for polishing small cavities as well as large substantially flat surfaces.
SUMMARY OF THE INVENTION In one embodiment, the present invention provides an apparatus for polishing a surface comprising: a polishing head comprising a plurality of flap assemblies; and a shaft attached to the plurality of flap assemblies for rotatably driving the polishing head.
BRIEF DESCRIPTION OF THE DRAWINGS For a detailed understanding of embodiments of the present invention, reference is made to the following detailed description of example embodiments, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals, wherein:
FIG. 1 is a view of an example embodiment of a polishing tool for polishing a surface;
FIG. 2 is a view of another example embodiment of a polishing tool for polishing a surface;
FIG. 3A is a view of an example of a polishing head;
FIG. 3B is a cross-section of the polishing head of FIG. 3A;
FIG. 4 is an exploded view of an example of upper and lower material layers with at least one stiffener element between the upper and lower material layers;
FIG. 5 is a cross-section of a flap assembly showing upper and lower material layers with stiffener elements;
FIG. 6 is a cross-section of a plurality of stacked flap assemblies;
FIG. 7 is a view of another shape for a material layer;
FIG. 8A is a view of an example of a material layer having a substantially circular bulbous tip;
FIG. 8B is a view of substantially elliptical bulbous tip;
FIG. 9A is an exploded view of one example of a flap assembly;
FIG. 9B is a view of the assembled flap assembly of FIG. 9A;
FIG. 10 is a view of another flap assembly;
FIG. 11 is a view of one example of a flap material layer having a textured surface; and
FIG. 12 is a view of another example of a flap material layer having a textured surface.
DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, in one example embodiment, a polishing tool 10 comprises a polishing head 20 coupled to a handle assembly 30. Polishing tool 10 may be coupled to a rotary power device 40 to rotate polishing head 20. In one example embodiment, polishing head 20 comprises a plurality of flap assemblies 21 attached to a shaft 22 extending at least partially upward through the center of polishing head 20.
In the example embodiment shown in FIG. 1, shaft 22 extends through an axial bore (not shown) in housing 31, and protrudes out of the bottom of housing 31. The bore in housing 31 acts to support and guide shaft 22 during rotary motion of shaft 22. The protruding portion of shaft 22 may be coupled to chuck 41 of rotary power device 40. In one example, rotary power device 40 is a cordless portable drill. Alternatively, corded electric drills or air driven rotary devices may be used. Folding handle 32 is pivotally attached to housing 31 by a pin 33. As shown, handle 32 may be folded around housing 31 in position 32′, or may be extended as shown. When extended, handle 32 may provide better support and control of the polishing tool as the polishing head interacts with a surface to be polished.
Housing 31 may be made of a plastic material, a metal material, or a combination of a plastic material and a metal material. Likewise, shaft 22 may be made from a plastic material, a metal material, or a combination of a plastic material and a metal material. Suitable plastic materials may comprise polyethylenes, polycarbonates, nylons, polypropylenes, polyvinylcarbonates, polyurethanes, and polyethylene terephthalate (PET). Suitable metal materials may comprise steel, aluminum, aluminum alloys, brass, and bronze.
In another embodiment, see FIG. 2, polishing tool 110 comprises a polishing head 120 coupled to a handle assembly 130. Polishing head 120 comprises a plurality of flap assemblies 21 attached to shaft 122. Shaft 122 extends below polishing head 120 and is sized to attach to handle assembly 130 at coupling 27. Coupling 27 connects shaft 122 to handle shaft 28. Handle shaft 28 extends through an axial bore (not shown) in housing 31. Handle shaft 28 may be attached to rotary power device 40 by chuck 41. Shaft 122 and handle shaft 28 may be made from plastic materials, metal materials, and combinations thereof as previously described. Folding handle 32 is pivotally attached to housing 31 by a pin 33. As shown, handle 32 may be folded around housing 31 in position 32′, or may be extended as shown. When extended, handle 32 may provide better support and control of the polishing tool as the polishing head interacts with a surface to be polished.
FIG. 3A shows a view of polishing head 20. It will be appreciated that the difference between polishing head 20 and polishing head 120 is the difference in length of shafts 22 and 122. The following description of the arrangement and construction of the plurality of flap assemblies 21 applies to both polishing head 20 and polishing head 120. Referring also to FIGS. 3B-5, each flap assembly 21 may comprise an upper material layer 51 and a lower material layer 53 with two stiffener elements 52 located between upper material layer 51 and lower material layer 53. In one embodiment, the width W of upper material layer 51 and lower material layer 53 is in the range of about 4.5 inches (114 mm) to about 5 inches (127 mm). FIG. 4 shows an exploded partial view of one example of the construction of flap assembly 21. FIG. 5 is a cross-section of a flap assembly showing upper and lower material layers with stiffener elements. In FIG. 4, only one stiffener element 52 and a cutaway upper material layer 51 are shown for clarity above a full lower material layer 53. Upper material layer 51 and lower material layer 53 may comprise a cloth material and/or a foam material. In one embodiment upper material layer 51 and lower material layer 53 comprise a polyester and polyamide microfiber fabric. Alternatively, natural fiber materials may be used, including felt, wool, mohair, cotton, and linen. In one example, stiffener element 52 may be made of an elastomer or plastic foam material having a stiffness greater than the stiffness of upper material layer 51 and lower material layer 53. Stiffener element 52 provides sufficient rigidity to force upper material layer 51 and lower material layer 53 of flap assembly 21 to extend substantially radially outward from shaft 22 during rotation of polishing head 20. Alternatively, at least one unstiffened material layer (not shown) may be interleaved between flap assemblies 21.
In one embodiment, upper material layer 51 and lower material layer 53 may be attached to stiffener 52 by any suitable technique, for example, by an adhesive, by stitching, or a combination of adhesive and stitching. As shown in FIGS. 4 and 5, stiffener element 52 is located inboard from the edge of material layers 51 and 53, such that a predetermined length L of unsupported material makes first contact with the workpiece surface. The flexible, unsupported material may enhance the polishing action of the material when the material interacts with the workpiece surface. There is a gap H between the stiffeners 52 in each flap assembly. Gap H provides access for stitching multiple layers together as shown in FIG. 3B and FIG. 6, where a plurality of flap assemblies 21 are stacked and stitched together along stitch lines A and B that may extend along the length of upper material layer 51 and lower material layer 53. The stitched stack allows for insertion of shaft 22 between two flap assemblies 21, see FIG. 3B. The attached flap assemblies may be attached to shaft 22, for example, using an adhesive. In other embodiments, upper material layer 51 and lower material layer 53 may comprise multiple layers of material attached together by adhesive and/or stitching.
The upper and lower material layers 51 and 53 may be shaped having varying widths such that both small and large workpiece features may be polished using the same polishing head. For example, FIG. 4 shows a substantially bullet shaped layer having a large relatively constant width section P1 for polishing relatively flat surfaces, and a smaller tapered width section P2 for polishing smaller surfaces and/or cavities. In use on automotive surfaces, for example, the large relatively constant width section P1 may be used for polishing, for example, fenders, hoods, and trunk lids. The smaller tapered width section P2 may be more useful for polishing, for example, around door handles and/or within wheel spokes.
FIG. 7 presents another example shape for a material layer 60 for the polishing head wherein the edges S1 and S2 taper substantially linearly from a relatively small width at each end to a relatively large width W near the center of each side.
FIG. 8A shows another example shape for a material layer 70 for the polishing head. Layer 70 comprises a main section 71 for polishing large surfaces, and a bulbous tip 72 for polishing small areas and openings. In the example embodiment shown, there are at least three polishing areas S3, S4, and S5 of differing shapes for polishing a variety of different surfaces on a workpiece. In FIG. 8A, bulbous tip 72 is substantially round having a radius R. In one embodiment, the radius R is about 0.5 inch (13 mm). In another embodiment, see FIG. 8B, a bulbous tip 75 may have an elliptical shape.
FIGS. 9A and 9B show another example embodiment of a flap assembly 110 that may be used with polishing heads 20 and/or 120, described previously. Flap assembly 110 may comprise an upper material layer 90 and a lower material layer 91 with stiffener elements 95 located between upper material layer 90 and lower material layer 91. In one example, material layers 90 and 91 may comprise a polyester and polyamide microfiber fabric, a felt material, a wool material, a mohair material, a cotton material, a linen material, and combinations thereof. Stiffener elements 95 may comprise an elastomer or a plastic foam material having a stiffness greater than the stiffness of upper material layer 90 and lower material layer 91. In one example, upper material layer 90 and lower material layer 91 may comprise a textured pattern 98. For example, textured pattern 98 may be formed into the material. Textured pattern 98 may comprise a hexagonal pattern, as shown. Alternatively, textured pattern 98 may comprise any suitable geometric pattern.
Upper material layer 90 and lower material layer 91 may be attached to stiffeners 95 by any suitable technique, for example, by an adhesive, by stitching, or a combination of an adhesive and stitching. A plurality of flap assemblies 110 may be assembled together using the techniques described previously with reference to FIG. 3B and FIG. 6. The assembled flap assemblies may be attached to shaft 22 or shaft 122 as described previously.
In another example, referring to FIG. 10, a flap assembly 121 may have a cutout 96 located on one side of a centerline 94 of an upper material layer 93 such that a foam stiffener element 95 is accessible through cutout 96. The placement of cutout 96 on one side allows the foam stiffener element material to be accessed for polishing a surface when the rotary power device is driven in a first direction, and the material layer is accessible for buffing when the rotary power device is driven in an opposite second direction. Any number of such cutout flap assemblies 121 may be assembled together, as described previously. In one example, stiffener element 95 may comprise an open cell plastic foam material that holds a polishing compound, for example a polishing wax, during the polishing process. It will be understood that a similar cutout may be formed in lower material layer 91.
FIG. 11 shows one example of material layers 90 or 91 having a textured pattern, for example, a textured pattern 98 formed in the material layer. In the example shown, a hexagonal pattern may be formed in the material layer. In one example, an outline perimeter 97 may be raised with respect to a hexagonal surface 99. Alternatively, hexagonal surface 99 may be raised with respect to outline perimeter 97. The portion that is not raised, that is the lower feature, may provide a collection area for dirt and/or used polishing compound collected on the material layers during the polishing and/or buffing process. As indicated previously, any suitable textured geometric pattern may be used.
FIG. 12 shows an example of an upper or lower material layer 100 that has an internally arched lower edge 102 that may provide for increased hand clearance when used in an assembled polishing head, for example polishing heads 20 and 120, described previously.
The foregoing description is intended for illustration and should not be construed as limiting the scope of the invention in any way. Those skilled in the art will recognize many variations that may be made without departing from the scope of the disclosed invention.
